As a conventional technology of this type, there is one disclosed in Patent Document 1. This conventional technology has a configuration that a main muffler through which exhaust gas from an engine is guided is disposed on an upperstructure of a construction machine, an exhaust outlet portion, specifically a tailpipe is connected to the main muffler, and a passage with the tailpipe inserted therein is defined through a counterweight disposed at a lower position in a rear section of the upperstructure. Also defined in the counterweight are a cavity communicating with the above-mentioned passage and an exhaust bore for externally releasing exhaust gas guided to the cavity.
According to the conventional technology configured as described above, the exhaust gas guided from the engine via the main muffler, the tailpipe and the cavity of the counterweight is externally released from the exhaust bore of the counterweight located in the lower part of the upperstructure.